Process of coating materials having an iron or steel base



May 31, 1927. 1,630,?

L. A. WYND ET AL PROCESS OF COATING MATERIALS HAVING AN IRON OR STEELBASE Filed Feb. 26, 1926 ln'szz'sn-r c2215..

LPate ntd May 31, 1 927.

UNlTED STATES PATENT OFFICE.

, LEO A. WYND Am) JULIAN L. scnunnnia, or rnoam, rumors.

PROCESS COATING MATERIALS HAVING AN IRON OR STEEL BASE.

Application filed February 26, 1926. Serial No. 90,868.

This invention has reference'to a process.

of coating materials having an iron or steel base such as sheets, Wiresand like materials, particularly-the coating of wire used in the fenceindustry and for telephone and other purposes.

The principal object of this invention is to apply a heavy coatingofzinc on wire without recourse to heat-treatment, either prior to orafter coating, or the use of a high grade zinc. Such a coating may bebent around its own diameter without showing the least signs of crackingor flaking and the'coating will be smooth.

The invention has for a further object to permit higher speeds to beused for the for-- mation of a heavier coating than can be economicallydone by any other process of which we have any knowledge.

The invention has for a further object an improved cleaning process forthe wire prior to its entrance to the zinc bath andto allow the cleanwire to enter and leave the bath through a clean zinc system.

Galvanized wire which is to be used for fabricating purposes, and moreparticularly that which is to be used in the manufacture of woven wirefencing, should have a relatively heav'y coating of zinc in order to beable to withstand atmospheric rusting and corroding conditions, andprior to our invention, so far as we are aware. this was not possible,except at an increased cost of pro-- duction. I

The universal practice for testlng the relative value of zinc ongalvanized wire is by the so-called Preece or copper sulphate test.There are other tests, however, which are used for quantitativelydetermining the amount of spelter on galvanized Wire, such as dippingthe coating in caustic solution; in a suitable hydrochloric acidsolution; in a solution of hydrochloric acid and antimony chloride, andin alead acetate solution. The copper sulphate test, although notquantitative, is comparable when used under known conditions' oftemperature and strength and being a quick test, and one which can beperformed by anyone after a little experience, has come to be theroutine testing medium for galvanized wire coating. On the basis of suchtests as these. are determined the relative weights of coatings (eitherthin or heavy) referred to thruout this description.

At the present time, so far as we are aware, there are only threemethods in use whereby these heavy zinc coatings may be,

obtained by the hot process of galvanizin The first method is to passthe wire throng finely divided charcoal as it emerges from thegalvanizing bath. By such a process a relatively smooth coating may beobtained. This method. is principally used for making telephone andtelegraph wire. It hasserious drawbacks, however, from an economicstandpoint because the wire must travel at a very slow speed and a veryhigh grade zinc must be used and, furthermore, the coated wire cannotbe-subjected to the action of fence fabricating machines without thecoating cracking or fiaking'rofi of the iron base.

The second method is to cause the wire to travel at a relatively slowspeed through a zinc bath. the speed depending upon the gauge of thewire, the thickness of the coating desired and the length of the bathand then smoothing the coating by passing it between suitablev wipes.This method, too, has its economic drawbacksbecause it requires purezinc on account of the slow speeds required and it consequently lessensthe tonnage passing through a galvanized unit in a given time. The thirdmethod is to pass the wire through a galvanizing bath and then withoutwiping subject it to a heat-treatment. This process, too, is slower thanour process and more expensive to operate.

Therefore, by the use of our invention we are not only permitted to usehigher speeds for galvanizing wire but we, also, obviate the necessityof using wipes or other smoothing mediums and the necessity forheattreatment, either one or the other, heretofore consideredindispensible'in galvanizing operations. Anadvantage in eliminating thewipers is that a heavier coating is permitted to remain on the wire,which in ordinary processes is removed by the wipe as the coated wirespass therethrough. It will, therefore, be apparent to those skilled inthe art that the higher speed can be used because it is not necessaryfor the wire to be wiped nor to be immersed in a molten salt bath, noris it necessary to pass the coated wire through a heat-treating furnace.By

accompanyin drawing, in which a diagrammatic view ilustrates acontinuous galvanizing or coating apparatus, including a lead annealingbath; an acid bath, and a galvanizing tank adapted to contain the moltenzinc bath. There is eliminated from such an apparatus the usual andordinary wiping or smoothing mechanism, as well as a heattreatingfurnace used for heat-treat1ng the coating subsequent to the coatingoperation; also, there is eliminated the necessity for iving the wire aso-called preliminary car- Eonization before it enters the coating bath.

Our process is very simple. We have (hecovered that if a wire is given avery thorough cleaning prior to coating and if the wire is kept cleanuntil and while it enters the coating bath and also kept clean as 1tleaves the coating bath and the coated wire is removed from the bath ina substantially vertical direction, that a ver smooth coating will beobtained and a very eavy one at the same 7 time, which can be subjectedto the most severe bending or forming operations and still leave thecoating intact upon the wire.

The processes which are at present in ordinary use, and which we areabout to describe,

have special reference to the lower carbon wires, though not limited tothese, are used for fabricating fencin barb wire, and for furnace wherethe the manufacture of te ephone wire and the like.

The ordinary process of galvanizing wire consists in passing the wirethrough molten lead or through an annealing furnace which accomplishesthe same purpose, cooling the wire and then passing it into preferablymuriatic acid where it is subjected to a cleaning operation. It passesfrom the muriatic acid through a flux, then over a drier and into thecoating bath. As the wire leaves the bath it passes between asbestoswiping means of some kind-either pressure or lever wipes and these wipesremove the excess zinc; in some cases as much as 50% of the coatingwhich adheres to the wire. This leaves a very thin coating on the wire.

In the manufacture of te phone wire,

which requires a .heavy coatin the'wire is passed very slowly through aath of high grade zinc and as it leaves the baththe wlre passes througha bed of charcoal and tallow, which wipes and smoothes the coating butdoes not wipe it as heavily as the ressure wipes mentioned before. Inthe erman process, United States Letters Patent No. 1,430,648, the wirepasses through the coating bath and as it emerges from the bath the wirepasses over a skimming arrangement which does not materially remove ancoating, other than removing the dross an skimmings carried over andthen passes into a heat-treatment, to which the wire is subjected,smoothes the coating and makes it malleable and flexible.

Another method for applying a heavy coating to wire is the method wherethe wire is subjected to a so-called preliminary carbonizetion before itenters the coating bath. This preliminary treatment may take place in amolten bath of some salt, or some combination of molten salts, and isclaimed to allow a heavy coating to be carried on the wire which will beflexible. However, by this method it is also necessary to pass the wirethrough a wiping arrangement of some kind. By our process the wire afterbeing sub jected to the usual annealing is passed into a usual cleaningsolution, where it is subjected to a heavy current, approximately 110volts D. (3., the wire being in contact with the ositive side of thecurrent and a sheet of ead or some other suitable material beingconnected to the negative side of the current. This current drives anyforeign matter off of the wire and leaves the wires extremely clean,especially from the action of the cleaning solution, which is extremelyvigorous and activated when the current is passed through it. The wirethen passes directly 10? the cleaning solution into the coating at t Thewire enters the coating bath through a clean zinc surface and afterpassin through the zinc emerges from the bati through a similarl cleanzinc surface. The wire leaves the bat without passing through any wipinskimming or smoothing means of any ind and is con noted in substantiallya vertical direction after leaving the bath until the coating has set,after which the direction of the wire may be as desired.

No other process is known to us whereby a heavy coating of prime westernzinc may be applied to wire, and which is flexible, ma leable andsmooth, except the Herman process, United Stat Letters Patent No.

1,430,648, hereinbefore entioned. Prime western zinc is the usual zincused for coating is desired, such as for telephone or telegraph wire,where the coating is r uired to stand a bend around a mandrel twe vetimes the diameter of the wire, in which case recourse must be had tothe use of a very high grade zinc such, for example, as pureelectrolytic zinc or the equivalent thereof. The

difference between the high grade zinc and the prime western zinc is, ofcourse, well known and understood by those skilled in the art. By theordinary processesof applying such coatings prime western zine will notstand this bend test, as the coating will crack and eel off the wire uon subjecting it to theshghtest amount of ending.

The bending properties of wire coated by our process are remarkable inthat the coated wire may be wrapped around its own diameter, thenunwrapped and again wrapped around its own diameter without apparentlyaffecting the coating in any manner. There is no other p ocess known tous of any kind whereby this may be done with a heavy prime western zinccoating.

In order to keep the surface of the wire clean at the entrance and-exitends of the coating bath, we apply small amounts of salammoniac or someother suitable material at suitable intervals in order to keep foreignmatter removed from said surface.

We are aware that the method of clean-' ing per se is not new, nor isthe addition .of salammoniac to zinc baths new, nor is the removal ofthe wire from the zinc bath in substantially a vertical direction new,but the process as described by us, we believe, is new and producesresults heretofore considered impossible with a coating of prime westernzinc, and which could be produced with a very high grade zinc only undervery carefully controlled conditions, which are far more expensive tooperate than our process.

Our process is the cheapest one known to us for producing heavy zinccoatings, and

more tonnage per coating unit can be obtained than by any other processknown to us for producing heavy coatings of zinc on wire.

The diagrammatic view accompanying this descri tion shows a preferredform of apparatus by means of which the within describedprocess may bepracticed, and is ofiered to show a mode of application in which anannealing furnace 1, a cleaning bath 2 and a coating tank 3 are placedinsubstantially the relative positions they will occupy when emplo ingthe process. A wire A is shown threa ing through in the act of beingcoated.

, At the entrance end of the cleaning bath there is illustrated apositive contact 4 with which the wiresA engages, and within thecleaning bath 2 there 1s provided a ne ative connectlon 5, which may beprefera 1y 8. lead sheet, arranged across the bottom of the cleaningbath and within the cleaning solution. These elements 4 and 5, as, ofcourse, will be understood, are connected in a suitable manner to asource of electric supply not shown.

The coating tank 3 is provided at its entrance end with a compartment 8and its exit end a similar com artment 9. These compartments are bothormed by means of aprons 10. Above the compartments 8 and 9 are arrangedfeedin receptacles 6 and 7 respectively, containlng suitable mechanisms,not shown, by means of which a suitable amount of salammoniac may beadded at suitable intervals to compartments 8 and 9 respectively.

The amount of salammoniac added, and the intervals at which it is added,depends ling, but in any case the amount added is very small.

In substance, our process consists in producing a heavy, flexible andmalleable coating of prime western zinc on wire without recourse to aheat-treating process and in which we eliminate the usual wiping orsmoothing or skimming mechanisms, or heat-treating apparatus for thecoating. It is obvious, of course, that as we produce such a coating, ashas been described, using prime western zinc that we can readily do sousing a high grade zinc.

The coating which is formed on the wire by our process, using .primewestern zinc, is extremely malleable and flexible and has a very brightsilvery color,'wh ich it retains for a long period of time. This coatinghas properties heretofore considered impossible to obtain with primewestern zinc, and which prior to our invention has been impossible toduplicate by any process known to us. It is true, of course, that theheat-treating process of Herman, United States Letters Patent No.1,430,648, produces a malleable coating using prime western zinc but itis not as malleable or flexible as the coating produced by our processand we have eliminated the necessity "for heat-treating the coating.

The terms and expressions which we have employed are used as terms ofdescription and not of limitation and we have no intention in the use ofsuch'terms and expressions of excluding any equivalent for the featuresshown and described, and recognize that various modifications arepossible within the scope of the invention claimed.

This application is a companion to the application filed by applicantson March 20, 1926, for a galvanizing apparatus bearing Serial No.96,301.

I What we claim is 1. A process for applying smooth zinc coatings toiron or steel wire, independent of wiping, which consists in subjectingthe wire to an activated cleaning prior to its entrance to a coatingbath, passing the wire thru the coatin bath, the entrance of the wireand the exit of the wire from the coating bath being throughsubstantially clean zinc surfaces.

.2. A process for applying smooth zinc coatin s to iron or steel Wire,which consists in subyecting the wire to an activated cleaning prior toits entrance to a coating bath, passing the wire thru the coating bath,the entrance of the wire and the exit of the wire from the coating bathbeing through substantially clean zinc surfaces, and conducting the wirefrom the bath in substantially a vertical direction whereby wiping isob-,

viated.

3. A rocess for a plying heavy flexible, malleabe and smoot coatings ofzinc to iron or steel wire independent of wiping,

qmalleab e and smooth coatm which consists in subjecting the wire to anactivated cleaning prior to its entrance to a coating bath, passing thewire thru the coating bath, the entrance of the wire and the exit of thewire from the coated bath being through substantially clean zincsurfaces.-

4. A process for applying heavy, flexible, malleable and smooth coatingsof zinc to iron or steel wire, which consists in subjecting the wire toan activated cleaning prior to its entrance to a coating bath, passingthe wire thru the coating bath, the entrance of the wire and the exit ofthe wire from the coated bath being through substantially clean zincsurfaces, and conducting the wire from the bath in substantially avertical direction whereby wiping is obviated.

5. A process for applying heavy, flexible, malleable and smooth coatingsof prime western zinc to iron or steel wire, indeendent of wiping, whichconsists in subecting the wire to an activated cleaning prior to itsentrance to a coating bath, passing thewwire thru the coating both, theentrance of the-wire and the exit of the wire from the coated bath beingthrough substantialy clean zinc surfaces.

6. A rocess for applying heavy, flexible, of prime western zinc to ironor stee wire, which consists in subjecting the wire to an activatedcleaning prior to its entrance to a coating bath, passing the wire thruthe coating bath, 'the'entrance of the wire and the exit of the wirefrom the coated bath being 40 through substantially clean zinc,surfaces, andconclucting the wire from the bath in substantially avertical direction whereby wi in --..,i s obviated.

X process for applying smooth a zinc coatings to 'n on or steelmaterial, independent of wi ing; which consists in subjecting thematerial to ail-activated cleaning prior to its entrance to a coatinbath, passing the material thru the coating ath, the entrance of thematerial and the exit of the material from the coating bath being thrusubstantially clean zinc surface.

LEO A. WYND. JULIAN L. SOHUELER.

